1. Field of the Invention
The present invention relates to exercise equipment, and more particularly refers to a method and device which may be used independently or in combination with conventional exercise regimen or equipment, and which device generates a series of pulse forces which are applied either directly or in combination with conventional exercise equipment to the muscles of a body member, e.g., a limb, trunk, foot, ankle, arm, leg, back, neck, or the like, of an exercising subject, thereby causing the muscles to stretch and to become stronger as a result of the stretching. The device and method of the present invention are able to generate a force in the contracting muscle greater than that attainable by voluntary contraction, which is a distinguishing feature which sets the present device and method apart from all previous exercise devices and methods. For example, according to the invention, a muscle is contracting at or near its maximum voluntary contractile force at a particular joint angle or position when a sudden pulse stretches the muscle a small distance, a stretching which results in a force in the muscle greater than that which could be voluntarily produced by the individual, the consequence being a greater strengthening effect than is attainable on any existing equipment or according to any available method.
2. Description of the Prior Art
There is general agreement among the authorities as expressed in the literature that, in order for a muscle to be strengthened, it must be loaded and that, for a muscle to be optimally strengthened, it must be overloaded or exercised until there is fatigue. This principle has been advanced over a long period of time. There is a story going back to the early Greeks, which tells of a man named Milo who lifted and carried a calf every day. As the calf gradually grew larger and heavier, Milo had to exert a greater force each day to carry the calf. Because the daily increasing force provided continually more severe exercise, Milo was able to carry the calf even after it had grown into a full-sized cow. There is also a classic article by an army colonel named Delorme who specifically looked at the use of barbells and so-called free weights to establish a regimen for overloading the muscle and thereby strengthening it. These are called "progressive resistance exercises".
There are basically several common types of exercises: (1) Isometric; and (2) Isotonic. In an isometric exercise the muscle contracts but the limb is held fixed against some object. The general concensus is that isometric exercises are limited in their ability to dramatically increase strength, and that the strength is only increased in the position in which the exercise is produced.
Isotonic exercises imply the contraction of muscle through a range of motion. Isotonic exercises may be subdivided into concentric and eccentric exercises. Concentric exercises are those in which the muscle shortens as force is applied: and eccentric exercises are those in which the muscle lengthens as force is applied. An isotonic exercise may involve the use of a free weight such as a barbell or a weight machine.
In the past many weight machines have been developed and marketed by companies such as Universal, Nautilus, Paramount, Marcy, and a number of others. These weight machines generally apply a constant weight force to the joint throughout the entire range of motion. In the case of the Nautilus machine a variable resistance force is applied so that the resistance force applied to the limb is somewhat proportional to the mechanics of the average limb in terms of being able to generate force throughout the range of motion.
Some of the prior art devices referred to create resistance force by the use of weight stacks. Other devices use hydraulic resistance force, and still other devices utilize electromagnetic brakes in order to provide resistance force. This latter system is used by Cybex and by the new Paramount equipment as well as by Toro.
Other devices of the prior art have used vibrating beds or tables for release of congestion, prevention of decubitous ulcers, improvement of circulation, and relief of back pain. Other devices have utilized electrical stimulation. However, none of these devices has proven to be sufficiently effective in strengthening muscles.